1. Field of the Invention
The present invention relates to an airbag jacket activating system. More specifically, the present invention relates to an airbag jacket activating system configured to make radio communications with a vehicle.
2. Description of Background Art
Keyless entry systems configured to carry out locking and unlocking operations through radio communications with a portable transceiver have been heretofore used for vehicles such as automobiles and motorcycles. For example, Japanese Patent Application Publication No. 2006-22606 discloses a keyless entry system in which a low-frequency (LF) request signal is transmitted from a vehicle to a portable transceiver and once the portable transceiver verifies this request signal, the portable transceiver transmits a high-frequency (RF) response signal to the vehicle.
An apparatus configured to make radio communications with a vehicle such as a keyless entry system may include an airbag jacket. The airbag jacket is an apparatus configured to reduce the influence of a large external force on a rider by deploying an airbag when the large external force is applied to the vehicle. It is conceivable that the above-mentioned multiple frequency bands may be applied to the system configured to activate this airbag jacket.
In this respect, the LF band makes it difficult to transmit data through coding the data because: the modulation amount is small and the quantity of data transmittable per unit time length is accordingly small. On the other hand, the RF band makes it easy to code data because the modulation amount is large and the quality of data transmittable per unit time length is accordingly large. Nevertheless, the RF band is likely to deteriorate the quality of the radio communications, for example, in a strong electric field area near a broadcasting station.
For this reason, when an ignition signal for the airbag and an ID signal are transmitted from the vehicle to the airbag jacket by use of the LF band, the uncoded ID is likely to be read by a third party. On the other hand, when the ignition signal and the ID signal are transmitted from the vehicle to the airbag jacket by use of the RF band, the signals are likely to be received improperly due to the deterioration in the quality of the radio communications.